u.s. department of commerce national oceanic and ... · registry nos. hydrographic title sheet...

U.S. DEPARTMENT OF COMMERCE

NATIONAL OCEANIC AND ATMOSPHERIC ADMINISTRATION

NATIONAL OCEAN SERVICE

Data Acquisition and Processing Report

Type of Survey Shallow Water Multibeam

Hydrographic and Side Scan Sonar Survey

Project No. OPR-J364-KR-10

Locality

State Florida

General Locality Gulf of Mexico

Sub-locality Florida Safety Fairways

South of Entrance to

Choctawhatchee Bay

2010

George G. Reynolds

CHIEF OF PARTY

Library & Archives

Date………………………………………………..

HYDROGRAPHIC TITLE SHEET

REGISTRY NOs.

H12236, H12237

State Florida

General Locality Gulf of Mexico

Sub-Locality Florida Safety Fairways South of Entrance to

Choctawhatchee Bay

Scale 1:40,000

Date of Survey April 5, 2010 – May 28, 2010

Instructions Dated Preliminary, March 8, 2010, Final, June 8, 2010

Project No. OPR-J364-KR-10

Vessel R/V Ferrel – USCG Official Number 1182802

Chief of Party George G. Reynolds

Surveyed By Robert M. Wallace, Bonnie L. Johnston, Kerry H. Cutler,

Alexander G. Unrein, John R. Bean, John R. Ayer,

Joseph V. Tyler

Soundings by

echo sounder Reson Seabat 7101

Verification by Michael J. Engels

Soundings in Meters (MLLW)

REMARKS: All Times Recorded in UTC

Data Recorded and Presented relative to UTM Zone 16 North

Contractor: Ocean Surveys, Inc.

129 Mill Rock Rd. East

Old Saybrook, CT 06475


THE INFORMATION PRESENTED IN THIS REPORT AND THE ACCOMPANYING

BASE SURFACES REPRESENTS THE RESULTS OF SURVEYS PERFORMED BY

OCEAN SURVEYS, INC. DURING THE PERIOD OF 5 APRIL 2010 TO 28 MAY 2010

AND CAN ONLY BE CONSIDERED AS INDICATING THE CONDITIONS EXISTING

AT THAT TIME. REUSE OF THIS INFORMATION BY CLIENT OR OTHERS BEYOND

THE SPECIFIC SCOPE OF WORK FOR WHICH IT WAS ACQUIRED SHALL BE AT

THE SOLE RISK OF THE USER AND WITHOUT LIABILITY TO OSI.

- i - Data Acquisition and Processing Report

TABLE OF CONTENTS Page

A. EQUIPMENT ................................................................................................................................................. 1

A.1 Survey Vessel ........................................................................................................................................ 1 A.2 Acquisition Hardware ............................................................................................................................ 3

A.2.1 Multibeam Echo Sounder System - Reson SeaBat 7101 ............................................................. 4 A.2.2 Vessel Navigation Systems ......................................................................................................... 4

A.2.2.1 Primary Positioning: Applanix POS MV ..................................................................... 4 A.2.2.2 Secondary Positioning: Trimble MS750 ...................................................................... 5 A.2.2.3 Differential GPS Correction: Trimble Pro Beacon DGPS Receivers............................ 5 A.2.2.4 Precise Positioning: Trimble 5700 GPS ....................................................................... 5

A.2.3 Attitude and Heading Measurement System – Applanix POS MV ............................................. 6 A.2.4 Side Scan Sonar System – Klein 5000 ........................................................................................ 6 A.2.5 Sound Speed Determination Systems .......................................................................................... 7

A.2.5.1 Water Column Profiles: ODIM MVP30 Moving Vessel Profiler ................................ 7 A.2.5.2 Water Column Profiles: SBE 19+ SEACAT Profiler CTD ......................................... 7 A.2.5.3 Surface Sound Speed: SBE37 ...................................................................................... 8

A.2.6 Lead Line and Stadia Rod ........................................................................................................... 8 A.2.7 SSS Cable Out Indicator .............................................................................................................. 9 A.2.8 Bottom Sampler ........................................................................................................................... 9 A.2.9 Hazen Tide Gauge ....................................................................................................................... 9

A.3 Computer Hardware and Software ...................................................................................................... 10

A.3.1 HYPACK .................................................................................................................................. 11

A.3.1.1 Vessel Navigation ....................................................................................................... 11 A.3.1.2 Multibeam Data Acquisition ....................................................................................... 11 A.3.1.3 Multibeam Data Processing ........................................................................................ 12

A.3.2 Chesapeake Technologies, Inc. (CTI) SonarWiz ...................................................................... 12

A.3.2.1 Side Scan Sonar Data Acquisition .............................................................................. 12 A.3.2.2 Towfish Layback and Position Computation .............................................................. 13

A.3.3 L3 Klein SonarPro ..................................................................................................................... 13 A.3.4 CARIS Hydrographic Information Processing System (HIPS) and Sonar Image Processing

System (SIPS) ........................................................................................................................... 13 A.3.5 CARIS Notebook ...................................................................................................................... 13 A.3.6 CARIS Easy View ..................................................................................................................... 14 A.3.7 AutoCAD 2004 ......................................................................................................................... 14 A.3.8 Microsoft Office Word and Excel ............................................................................................. 14 A.3.9 Adobe Acrobat .......................................................................................................................... 14 A.3.10 Global Mapper 10 .................................................................................................................... 14 A.3.11 Applanix MV-POSView ......................................................................................................... 14 A.3.12 Applanix POSPac MMS Post-Processing Data ....................................................................... 15 A.3.13 Hydrographic Consultants, Ltd. CALLOAD........................................................................... 15 A.3.14 Trimble MS Controller ............................................................................................................ 15 A.3.15 Trimble ProBeacon .................................................................................................................. 15 A.3.16 ODIM Brooke Ocean MVP Controller ................................................................................... 15

A.4 Acquisition Procedures ........................................................................................................................ 16

- ii - Data Acquisition and Processing Report

A.4.1 Project Management Overview ................................................................................................. 16 A.4.2 Project Planning ........................................................................................................................ 16 A.4.3 Data Acquisition Quality Control .............................................................................................. 16

B. PROCESSING AND QUALITY CONTROL .............................................................................................. 20

B.1 Data Flow and Processing Procedures ................................................................................................. 20

B.1.1 Sound Speed Profile Processing ................................................................................................ 20 B.1.2 SWMB Processing ..................................................................................................................... 20 B.1.3 Side Scan Sonar (SSS) Processing ............................................................................................ 26 B.1.4 S-57 Feature Processing ............................................................................................................ 31

C. CORRECTIONS TO ECHO SOUNDINGS ................................................................................................. 31

C.1 Vessel Configuration and Offsets ........................................................................................................ 31

C.1.1 CARIS Vessel Configuration Files and Device Models ............................................................ 31 C.1.2 Offsets and Uncertainty Estimates ............................................................................................. 33

C.2 Static and Dynamic Draft Measurements ............................................................................................ 34

C.2.1 Static Draft................................................................................................................................. 34 C.2.2 Settlement and Squat (Dynamic Draft) ...................................................................................... 34

C.3 Motion, Timing Errors and Sensor Alignment .................................................................................... 36 C.4 Water Levels ........................................................................................................................................ 38

D. APPROVAL SHEET

- 1 - Data Acquisition and Processing Report

A. EQUIPMENT

A.1 Survey Vessel

All survey operations were conducted from Reservoir Geophysical’s R/V Ferrel (Figure 1).

R/V Ferrel, O.N. 1182802, is a 44.5-meter steel vessel, with a 9.8-meter beam and 1.8-meter

draft. R/V Ferrel is powered by two CAT D 353 diesel engines rated at 750 HP.

Figure 1. R/V Ferrel configured for hydrographic survey operations.

The R/V Ferrel was modified by OSI to support hydrographic survey operations. The

following summarizes the major adaptations and/or custom survey support hardware installed

on the R/V Ferrel:

1. An ISO office container was installed on the main deck to house acquisition and

processing computer stations along with major survey system control modules and

computer systems.

2. An indexed Inertial Measurement Unit (IMU) mounting plate was installed on the

ship’s fore-aft (roll) centerline at the approximate pitch center of rotation. The POS-

MV IMU was installed on this plate which resides just below the plane of the ship’s

waterline on the lower deck.


3. A retractable multibeam transducer pole, constructed of thick-wall steel pipe, was

attached to the starboard side of the vessel at the approximate pitch centerline. The

pole was attached at two points; a “saddle plate” on the deck of the vessel and a

“receiver plate” at the chine of the vessel. The transducer pole is secured, by means

of a wire rope winch connection, into the V-notch receiver plate at the chine of the

ship, thereby eliminating pole movement. The transducer pole was fitted with

fairings on the trailing edge to minimize cavitation. The transducer was not moved or

adjusted after completion of the initial system alignment calibration (patch test).

4. A Hazen tide gauge was installed within the transducer pole to monitor static draft.

5. A hydraulically actuated A-frame was installed on the starboard quarter of the ship.

The SSS towfish was flown from the A-frame. Two (2) electric/hydraulic multi-

purpose slip ring winches (SSS primary and spare) were installed on the main deck.

A moving vessel profiler (MVP) was installed on the port quarter of the ship.

6. Reference points were established on the vessel to define a fixed reference frame,

vessel reference point (RP), draft measurement locations and sensor mounting

locations. These points were “surveyed” using a precision total station optical

theodolite and electronic distance meter. Survey offsets and estimated measurement

accuracies were incorporated into the CARIS vessel configuration file. Refer to

Section C.1 Vessel Configuration and Offsets for additional details.


A.2 Acquisition Hardware

Major data acquisition system components employed on this survey are summarized in Table

1 below. A brief description of the equipment follows.

Table 1

Acquisition Hardware

System Data Manufacturer Model/

Version No.

Firmware

Ver.

Serial

Number (s)

Multibeam Echo

Sounder Soundings Reson 7101 MR 7.1 3707078

Side Scan Sonar Imagery/Contacts Klein 5000 11.3 357

Moving Vessel

Profiler Sound Speed ODIM MVP-30 1.0 10648

Sound Speed

Profiler Sound Speed Sea-Bird

SeaCAT SBE

19+ CTD 2.1 6513

Sound Speed

Sensor

(Real-Time

Surface Water

Sound Speed)

Sound Speed Sea-Bird MicroCAT

SBE37 2.2 7531

Primary

Navigation DGPS Position

Applanix/

Trimble

POS MV 320

V.4

HW 2.5-6

SW 03.42

TPU 2149

IMU 390

Secondary

Navigation DGPS

(Position Integrity

Alarm)

Position Trimble MS750 1.58 220209817

Vessel Attitude

and Heading

Pitch, Roll,

Heave, Heading

Applanix/

Trimble

POS MV 320

V.4

HW 2.5-6

SW 03.42

TPU 2149

IMU 390

U.S.C.G.

Differential

Beacon Receivers

(2)

GPS correctors Trimble ProBeacon 3 0220033958

0220181939

Lead Line Soundings OSI Lead Disk N/A 1

Stadia Rod Static Draft Crain CR-4.0M N/A OSI SR-02

SSS Cable Payout

Indicator

SSS Fish

Layback

Hydrographic

Consultants SCC16” 2 1603

Land Survey GPS Position Trimble 5700 V3.01 220332818

Pipe Dredge Bottom Samples N/A N/A

Tide Gauge Static Draft Hazen HTG5000 N/A 363764R


A.2.1 Multibeam Echo Sounder System - Reson SeaBat 7101

The SeaBat 7101 is a 240 kHz Multibeam Echo Sounder (MBES) System, which measures

the relative water depths across a 150º wide swath perpendicular to a vessel’s track. The

7101 system illuminates a swath of the seafloor that is 150º across track by 1.5º along track.

The system can be configured to collect 239 or 511 equidistant beams or 101 equiangular

beams with a depth resolution of 1.25 cm. For this project, the Reson 7101 was operated in

the 511 equidistant beam mode. The installed system was equipped with the Extended

Range projector and designed to comply with International Hydrographic Organization

(IHO) standards to measure seafloor depths to a maximum range of 500 meters.

Digital data were output through the Ethernet data port and displayed in real time on a high-

resolution color monitor. Power and gain settings were monitored and adjusted to optimize

bottom detection for the inner 140 degrees of swath coverage. Range settings were

monitored and adjusted for observed depths to maximize ping rates.

UTC date and time information from the POS MV was used to accurately time stamp the

Reson output data string. The Reson 71P processor also received a pulse-per-second (PPS)

and a serial $ZDA NMEA timing string from the POS MV.

Transducer offsets and mounting angles, relative to the vessel frame and a vessel reference

position (RP), were measured using standard optical survey equipment and techniques.

Residual alignment and calibration offsets were documented in the patch test results. Refer

to Section C.1 Vessel Configuration and Offsets for additional details.

A.2.2 Vessel Navigation Systems

A.2.2.1 Primary Positioning: Applanix POS MV

An Applanix POS MV 320 V.4 system was installed on the survey vessel to provide position

and attitude data. The POS MV (Position and Orientation System for Marine Vessels)

consists of a rack mountable POS Computer System (PCS), a separate Inertial Measurement

Unit (IMU) and two GPS receivers.

The POS MV combines the IMU and GPS sensor data into an integrated and blended

navigation solution. There are two navigation algorithms incorporated into the system,

namely tightly coupled and loosely coupled inertial/GPS integration. Tightly coupled

inertial/GPS integration involves the processing of GPS pseudorange, phase and Doppler

observables. In this case, the GPS receiver is strictly a sensor of the GPS observables and the

navigation functions in the GPS receiver are not used. With loosely coupled inertial/GPS

integration, the GPS position and velocity solution are processed to aid the inertial navigator.

The POS MV received United States Coast Guard differential beacon corrections (DGPS).

In all cases, dockside navigation system accuracy testing demonstrated that the POS-MV,

employing USCG correctors, had an accuracy of better than 1.5 meters. DGPS outages were


infrequent. The real-time position accuracy alarm was set at 1.5 meters and monitored

during data acquisition using the MV-POSView controller software. Despite the infrequent

outages, at no time did the field team observe real-time accuracy degradation greater than

two meters.

IMU and antenna offsets and mounting angles, relative to the vessel frame and a vessel

reference position (RP), were measured with precise optical survey methods. The primary

GPS antenna position, with respect to the IMU and RP, was confirmed using the MV-

POSView controller calibration procedure. Residual alignment and calibration were derived

during the patch test procedure. Refer to Section C.1 Vessel Configuration and Offsets for

additional details.

A.2.2.2 Secondary Positioning: Trimble MS750

A secondary or “position integrity alarm” GPS system consisted of a Trimble MS750 GPS

operating in DGPS mode. The secondary system position was compared to the primary

position system and monitored continuously in HYPACK during survey operations.

A.2.2.3 Differential GPS Correction: Trimble Pro Beacon DGPS Receivers

Trimble Pro Beacon DGPS beacon receivers were manually tuned to local USCG differential

beacon stations and interfaced to each of the aforementioned GPS systems. Refer to the

Horizontal and Vertical Control Report (HVCR) for additional details of DGPS position

correctors.

A.2.2.4 Precise Positioning: Trimble 5700 GPS

Prior to and during the course of the survey the accuracy of the primary positioning system

was verified by means of a physical measurement to a project temporary horizontal

control/navigation checkpoint located at the vessel’s berth. The checkpoint was established

using a Trimble 5700 GPS system configured with a Trimble Zephyr Geodetic antenna. The

Geodetic antenna was installed over the project horizontal checkpoint and three (3) static

position observations were made. The recorded GPS data files were submitted to the

National Geodetic Survey (NGS) On-line Positioning User Service (OPUS) and processed to

determine the position of the temporary control point. Each data file that was submitted was

processed with respect to at least 5 CORS sites. NGS provided an OPUS Report which

included both ITRF and NAD83 coordinates along with position accuracy information. These

reports are provided in the HVCR.

Position confidence checks were accomplished at least bi-weekly, during fuel or weather

stops. The distance between the vessel steering point and the horizontal control point

computed by the navigation system was compared to the distance between the vessel

reference point and the horizontal control point measured with a steel tape. Details of the

horizontal control points are included with the HVCR. A tabulation of navigation system

performance checks is included with the Survey Descriptive Report (DR) Separate I.


A.2.3 Attitude and Heading Measurement System - Applanix POS MV

The POS MV generates attitude data in three axes (roll, pitch and heading) within 0.02

degree accuracy. Heave measurements supplied by the POS MV maintain an accuracy of 5-

centimeters or 5% of the measured vertical displacement for movements that have a period of

up to 20 seconds. The heave bandwidth filter was configured with a dampening coefficient

of 0.707. The cutoff period of the high pass filter was determined by estimating the swell

period encountered during the survey. A heave bandwidth filter of 10 seconds was employed

during data collection.

Applanix “TrueHeave” data were acquired and recorded during survey operations. The

TrueHeave algorithm uses a delayed filtering technique to increase heave measurement

accuracy, reducing error caused by IMU drift and long-period ocean swell. The TrueHeave

data corrections were applied to soundings during post processing in CARIS HIPS.

The GPS Azimuth Measurement Subsystem (GAMS) allows the POS MV system to achieve

high-accuracy heading measurement. The GAMS subsystem uses two GPS receivers and

antennas to determine a GPS-enhanced heading that is accurate to 0.02° or better (using a

two-meter antenna baseline) when blended with the inertial navigation solution. POS MV

uses this heading information as aiding data together with the position, velocity and raw

observations information supplied by the primary GPS receiver. GAMS operation was

employed for all survey data acquisition and GAMS status was monitored continuously

during survey operations using the MV-POSView controller software.

IMU and antenna offsets and mounting angles, relative to the vessel frame and a vessel

reference position (RP), were measured with a precise survey. An Applanix-specified

GAMS calibration procedure was conducted prior to survey data acquisition.

A.2.4 Side Scan Sonar System - Klein 5000

Side scan sonar imagery was acquired employing a Klein 5000 single-frequency sonar

operating at 455 kHz. The Klein 5000 system consists of a Transceiver Processor Unit

(TPU), coaxial double armored steel tow cable, winch, digital cable payout meter, and sonar

towfish. System components were interfaced to the acquisition system and other ancillary

devices, via a local network hub or serial cable connections.

The towfish was equipped with an optional pressure sensor which was used to measure towfish

depth. The pressure sensor was calibrated (depth zeroed) daily at the surface to account for

changes in atmospheric pressure. The pressure sensor data were interfaced and converted to

depth with Chesapeake Technologies, Inc. “SonarWiz” side scan sonar data acquisition system.

The TPU was interfaced with the primary navigation system through SonarWiz. Depth and

cable-out data were used by SonarWiz to determine the towfish position relative to the vessel

reference point.


The waterfall display within the Klein “SonarPro” side scan sonar data acquisition system was

employed in display mode only. Refer to Section A.3 Computer Hardware and Software for

additional details of side scan sonar data processing.

A.2.5 Sound Speed Determination Systems

The surface sound speed sensor, the sound speed profiler (CTD), and the ODIM MVP were

manufacturer calibrated before survey data acquisition. Copies of the calibration sheets are

included with the DR in Separate II.

A.2.5.1 Water Column Profiles: ODIM MVP30 Moving Vessel Profiler

The ODIM MVP30 Moving Vessel Profiler allows sound speed profiles to be collected while

the vessel is underway. The ODIM MVP consists of a towfish sensor, a conductor cable and

an electric winch. The MVP may be deployed manually using the winch controls or

remotely using the ODIM MVP Controller Software. When operated in “FreeWheel” mode

while underway, the MVP falls near-vertically to a preset depth off the bottom, collecting

sound speed and temperature/depth measurements at a frequency of 10Hz. Water sound

speed profiles in CARIS HIPS .SVP format were calculated from raw MVP data using

NOAA NOS Coast Survey Development Laboratory (CSDL) Velocwin software. All sound

speed corrections were applied in post processing with CARIS HIPS software. Refer to

section A.3 Computer Hardware and Software for additional details of sound speed data

processing.

A manual MVP cast was acquired daily while the R/V Ferrel was at a full-stop. The manual

cast data were compared with a simultaneously recorded CTD cast acquired with a SBE 19+

SEACAT Profiler CTD. The sound speed profiles from the MVP and CTD were compared

using Velocwin’s “Weekly DQA” tool. Daily comparisons were made between the surface

sound speed of the stationary MVP (and CTD cast) and the surface sound speed recorded by

the SBE37 at the time of the cast. The surface DQA comparisons were accomplished using

Velocwin’s “Daily DQA” tool. Listings of daily and weekly DQA results are included in DR

Separate II.

A.2.5.2 Water Column Profiles: Sea-Bird 19+ SEACAT Profiler CTD

Water column conductivity, temperature and pressure (depth) profiles were acquired using a

Sea-Bird Electronics (SBE) 19+ SEACAT Profiler CTD once per day when the R/V Ferrel was

at a full-stop. The SBE 19+ SEACAT Profiler acquires high resolution water column

measurements at a continuous rate of 4 Hz. Raw CTD data were uploaded via a serial port to a

designated PC following each cast.

Water sound speed profiles were calculated from raw CTD data using Velocwin software. The

CTD cast acquired with the SBE 19+ was compared to a manual MVP cast that was taken

simultaneously. Velocwin software was used to conduct Daily and Weekly DQA comparing

the surface sound speed of the CTD cast to the surface sound speed of the SBE37 at the time of


the cast and comparing the simultaneous sound speed profiles from the MVP and the CTD. A

tabulation of comparison sound speed casts and record of DQA results are included with the

DR Separate II.

A.2.5.3 Surface Sound Speed: SBE37

The SBE 37 is a high-accuracy conductivity and temperature sensor capable of calculating

and transmitting sound speed values via a standard RS232 serial data interface. The SBE 37

transmitted real-time surface sound speed data to the Reson 7101 multibeam system and the

HYPACK acquisition computer (via the Reson 7101 interface).

The SBE 37 was installed behind the multibeam transducer at the draft of the phase center.

Real-time surface sound speed values were transmitted to the Reson 71P topside unit and

subsequently recorded with multibeam echo sounder data in the raw HYPACK.HSX data

files. Sound speed data were also transmitted to the HYPACK acquisition software which

was configured to display a visual alarm if the surface sound speed exceeded a threshold of

± 3 m/s. Variations in surface sound speed were monitored and evaluated as an indicator of

surface water temperature/salinity fluctuation and potential water column variation which

would necessitate additional sound-speed profile measurements.

Daily sound speed quality assurance (DQA) checks were performed using NOAA CSDL

Velocwin software by comparing the SBE37 surface sound speed to the surface sound speed

of the MVP and CTD comparison cast sound speed profiles. A tabulation of daily DQA

results is included in DR Separate II.

Surface sound speed data were used by the Reson 7101 system for range determination.

However, all sound speed corrections used to calculate depths from raw data were performed

during post processing in CARIS HIPS using the full water column sound speed profile data.

A.2.6 Lead Line and Stadia Rod

Multibeam echo sounder accuracy checks were performed by means of a “bar check” or lead

line measurement comparison. The lead line was constructed of a 9 kilogram, 0.3-meter

round lead disk attached to a cable with permanent index markers established at measured 5-

meter intervals. The bar check procedure consisted of lowering the disk (acoustic target) to a

measured depth directly below the multibeam transducer and recording the nadir depth value.

A bar check was performed prior to survey data acquisition to confirm the transducer phase-

center vertical offset with respect to the vessel reference point. Subsequent bar checks were

performed at regular intervals to verify system performance and vertical offsets in the CARIS

HVF.

The lead line comparison procedure, or “spot check,” consisted of sounding the seafloor

directly below the multibeam transducer with the lead line while simultaneously observing

the multibeam nadir depth.


Prior to survey data acquisition, the lead line was calibrated with a steel survey tape to verify

index mark accuracy.

A fiberglass stadia rod was employed throughout the survey for various tasks requiring a

rigid measuring tool. Due to the relatively high freeboard of the R/V Ferrel, static draft

measurements were accomplished using the stadia rod. Prior to utilization, the rod

graduations were compared to a steel tape measure to confirm its accuracy.

A.2.7 SSS Cable Out Indicator

Determination of SSS cable out values was accomplished by means of a Hydrographic

Consultant, Ltd. SCC Smart Sensor Cable Payout Indicator. The payout indicator consists of

a topside display/controller, deck cable, and 16-inch (0.4-meter) diameter block fitted with a

magnetically triggered counting sensor.

The cable out indicator was calibrated according to manufacturer specifications before data

acquisition by measuring the sheave circumference and entering a calibration value into the

topside controller software. Cable out readings were verified daily at the beginning of survey

operations, and at regular intervals throughout the day, by observing measured index marks

on the towfish cable with respect to a reference position on the winch.

The cable out indicator was interfaced with Chesapeake Technologies, Inc. SonarWiz side

scan sonar data acquisition system. The length of cable deployed, along with towfish

pressure sensor information, was used to determine an accurate towfish position relative to

the vessel reference point. Refer to Section A.3 Computer Hardware and Software for

additional data acquisition details.

A.2.8 Bottom Sampler

A pipe dredge was employed to obtain seafloor sediment samples within the survey area. A

PowerWinch system aboard the R/V Ferrel was employed to recover the unit.

A.2.9 Hazen Tide Gauge

A Hazen tide gauge was used to calculate daily vessel static draft levels. The instrument

consists of a pressure transducer connected to a top-side transmitter. The transmitter is

powered by a rechargeable battery pack and it communicates to a remote receiver via cable

or a radio link.

The Hazen gauge transducer was installed below the waterline in the multibeam transducer

pole mount and configured to record a water level every 9 seconds. The transducer mounting

flange at the bottom of the transducer pole was fitted with a small diameter copper orifice

making the transducer pole, in effect, a stilling well. The receiver was interfaced with the

acquisition computer through a serial port and the water level reading was logged in meters

to a HYPACK .RAW file while the ship was at a full stop. See Section C.2.1 Static Draft for

a more detailed explanation of the Hazen gauge utilization.


A.3 Computer Hardware and Software

Computer hardware and software utilized during this survey are itemized in Table 2 below.

Table 2

Computer Software

Manufacturer Application Platform Version Version Date

HYPACK HYPACK SURVEY WXP 9.0 9.1.0.0 Sept. 28, 2009

HYPACK HYSWEEP SURVEY WXP 9.0.26.0 Sept. 28, 2009

Chesapeake Technology, Inc. SonarWiz 4 WXP 4.04.0061 Sept 8, 2009

Chesapeake Technology, Inc. SonarWiz RT WXP 1.0.8.0088 Jan 8, 2010

L3 Klein SonarPro WXP 11.2 Apr 24, 2007

L3 Klein VX, Works WXP 6.18 Feb 21, 2008

Universal Systems, Ltd. CARIS HIPS/SIPS WXP 6.1 June 1, 2008

Universal Systems, Ltd. CARIS Notebook WXP 3.0 June 5, 2008

Universal Systems, Ltd. CARIS Easy View WXP 2.0 2008

NOAA NOAA Velocwin WXP 8.92 May 8, 2008

Global Mapper Software LLC Global Mapper WXP 10 Aug 27, 2008

AutoDesk Inc. AutoCAD WXP 2004 Feb 14, 2003

Microsoft Office (WORD, EXCEL) WXP 2007 Oct 18, 2008

Sea-Bird Electronics SeaTerm WXP 1.59 Dec 22, 2008

Sea-Bird Electronics SBE Data Processing WXP 7.18b 2008

Applanix MV-POSView WXP 5.0.0.0 July 13, 2009

Applanix POSPac MMS WXP 5.2 Aug 25, 2009

Hydrographic Consultants CALLOAD WXP 2.0 Dec 18, 2005

Trimble MS Controller WXP 1.1.0.0 May 21, 2002

Trimble Pro Beacon PC Interface DOS 5.0 March 5, 1991

ODIM Brooke Ocean MVP Controller WXP 2.430 2009


A.3.1 HYPACK

A.3.1.1 Vessel Navigation

Survey vessel trackline control and position fixing were accomplished by using a computer-

based data-logging and navigation software package (HYPACK). Vessel position data were

output from the POS MV at 50 Hz frequency and transmitted to the navigation computer

system, which processed these data in real-time into the desired mapping coordinate system

(UTM Zone 16 North, NAD 83). Raw and processed position data were continuously logged

onto the computer hard drive and displayed on a video monitor, enabling the vessel’s

helmsman to guide the survey vessel accurately along pre-selected tracklines. Tracklines and

survey features were displayed on the helm monitor with geographic reference data that

included NOS raster nautical charts (RNC) and S-57 electronic nautical charts (ENC).

Multibeam echo sounder data were monitored in real-time using 2-D and 3-D data display

windows. Motion and predicted tide-corrected sounding data were displayed as HYPACK

gridded depth models and coverage matrices. HYPACK “targets” were also recorded to

mark the location and time of significant observations during data acquisition, such as CTD

cast positions.

Raw, geographic position data (NAD83 degrees latitude and longitude) were time tagged

with UTC time by the POS MV and recorded by HYPACK in .RAW format line files.

The HYPACK computer was also used for sensor monitoring and data quality review while

data were acquired. Utilities in the acquisition module of HYPACK notify the operator with

a visual alert in the event of a sensor malfunction or, in some cases, when a sensor parameter

drifts out of operator-set limits (e.g. DGPS position comparison or sound speed change).

A.3.1.2 Multibeam Data Acquisition

A dedicated computer was used to record all multibeam sounding data as well as all

associated vessel position, motion, and heading data. Multibeam data were logged with

HYPACK HYSWEEP software using a Windows XP computer which has a 3.16 GHz Intel

Core 2 Duo processor, a 320 gigabyte hard drive, a 2 terabyte hard drive and 4.0 gigabytes of

RAM. This computer was also used to monitor the MV-POSView controller, record POSPac

data, process water column sound speed data and maintain project and acquisition logs.

Multibeam raw beam ranges, intensities, and quality flags were time tagged with UTC time

by the Reson 71P processor and recorded by HYPACK in .HSX format line files.

Motion and attitude data (heave, pitch, roll, and heading) were time tagged with UTC time by

the POS MV and recorded by HYPACK in .HSX format line files.

Data were copied onto processing computers located on the ship for editing. Raw, processed

and supporting data (acquisition logs, svp profiles, etc.) were transferred to Ocean Surveys’

home office via courier delivery.


A.3.1.3 Multibeam Data Processing

The HYPACK HYSWEEP SURVEY calibration module was used to determine preliminary

alignment correctors from multibeam sonar calibration patch tests. All patch test values were

verified in CARIS HIPS and entered into the vessel configuration file. Refer to Section C.3

Motion, Timing Errors and Sensor Alignment.

A.3.2 Chesapeake Technologies, Inc. (CTI) SonarWiz

A.3.2.1 Side Scan Sonar Data Acquisition

A dedicated computer was used to record all side scan sonar data and display real-time side

scan sonar (SSS) waterfall and mosaic imagery. Side scan sonar data were logged with

SonarWiz software using a Windows XP computer which has a 3.16 GHz Intel Core 2 Duo

processor, a 320 gigabyte hard drive, a 2 terabyte hard drive and 4.0 gigabytes of RAM.

SonarWiz was configured to display slant-range corrected, scrolling waterfall displays of the

455 kHz frequency side scan sonar data during operations. Scrolling imagery was monitored

continuously for data quality and to identify significant features. Confidence checks observed

across the full range (e.g. sand waves, bottom changes and buoy blocks) were recorded

frequently to verify system operation and object detection capabilities. Confidence checks

were recorded with line names, observation times, and comments in the daily acquisition log.

Significant side scan contacts were targeted in the SonarWiz waterfall window, simultaneously

creating a target in HYPACK Survey. The HYPACK targets were tagged with a unique ID by

SonarWiz and updated with a descriptive field comment. All potential side scan contacts

selected from the real-time waterfall were saved to the daily HYPACK target file.

SonarWiz compiled side scan sonar data with vessel position, towfish position, layback and

cable out values and recorded raw data in .XTF format line files. Two hundred percent (200%)

SSS coverage was attained in the survey area employing line spacing and side scan sonar range

scales tabulated in Table 3 below.

Table 3

SSS Line Spacing and Range Scales

Trackline Offset

(meters)

SSS Range Scale

(meters)

65 75

65, 85 100

Vessel speed was maintained such that any 1m3

object would be ensonified more than three

times per pass at the operating range scale. In general, the towfish height was maintained at

8-20 percent of the range scale. Refraction effects were minimized in deep water by

changing the depth/altitude at which the towfish was flown.


Side scan data were copied onto processing computers located on the ship for preliminary

editing. Raw, processed and supporting data (acquisition logs) were transferred to Ocean

Surveys’ home office via courier delivery.

A.3.2.2 Towfish Layback and Position Computation

SonarWiz was configured to receive navigation data from the POS MV, pressure sensor data

from the towfish, and cable out from the topside cable counter controller. Towfish depth was

calculated from the pressure sensor data. Towfish layback was calculated in SonarWiz from

depth and cable out using Pythagorean’s Theorem and a percentage of cable out value to

correct for the catenary effect. The towfish position was calculated assuming that the towfish

was directly behind the vessel relative to the navigation track.

A.3.3 L3 Klein SonarPro

L3 Klein SonarPro software was operated in “slave mode” to the side scan sonar TPU and

configured to display an uncorrected, scrolling waterfall display of the side scan sonar data.

Scrolling imagery was monitored continuously for data quality and to identify water column

noise or interference (e.g. dolphins, boat wake, etc.).

A.3.4 CARIS Hydrographic Information Processing System (HIPS) and Sonar Image

Processing System (SIPS)

All multibeam echo sounder data were converted from raw HYPACK format data files to

HDCS format and processed using CARIS HIPS software Version 6.1 (Service Pack 2) for

the Microsoft Windows XP environment.

All SSS data were converted from raw .XTF format line files to HDCS format and processed

using the CARIS SIPS software, Version 6.1 (Service Pack 2) for the Microsoft Windows

environment.

Refer to Section B. PROCESSING AND QUALITY CONTROL.

A.3.5 CARIS Notebook

An S-57 attributed feature file was created in CARIS Notebook to emphasize navigationally

significant objects discovered during the survey and to provide information for these objects

that could not be portrayed in the BASE surfaces. New and updated chart features were

included in the S57 feature file for submission with the hydrographic survey data.

Refer to Section B. PROCESSING AND QUALITY CONTROL.


A.3.6 CARIS Easy View

CARIS Easy View (Service Pack 1) was used to review multiple sources of data during

processing, quality review and chart comparisons. Raster and vector reference data included

CARIS soundings, BASE surfaces, contours, HOB format files, S-57 000 format files, ENC,

RNC, and AutoCAD drawing exchange files (dxf).

A.3.7 AutoCAD 2004

AutoCAD drafting and geographic information system was employed for pre-survey

planning, line file construction, hydrographic data QC and the production of presentation

graphics.

A.3.8 Microsoft Office Word and Excel

MS Excel was used for log keeping (field and processing), sound velocity profile display and

review, organization and preparation of field and office tasks, report table production and

statistical data analysis. MS Word was used for report generation.

A.3.9 Adobe Acrobat

Adobe Acrobat was used to prepare final reports with digital signatures in accordance with

the Statement of Work (SOW), 2010 and the NOS Hydrographic Surveys Specifications and

Deliverables Manual (HSSD, 2010), April 2010.

A.3.10 Global Mapper 10

This 3-D visualization software and geographic information system was employed to create

detailed sun-illuminated Digital Terrain Model (DTM) images, display vector geographic

data and convert file formats. These data were used for QC checks and presentation

purposes.

A.3.11 Applanix MV-POSView

The MV-POSView controller software was used to configure and monitor the POS MV

navigation and inertial motion unit system. IMU, navigation and GAMS status were

monitored continuously at the navigation and acquisition stations. Visual alarms were

configured to alert the operator in the event that attitude, position, velocity, heading or heave

accuracy was degraded.

The MV-POSView controller was also configured to record TrueHeave, navigation and

motion correction data (POSPac).


A.3.12 Applanix POSPac MMS Post-Processing Data

POSPac data were acquired and logged during survey operations. POSPac MMS is a post-

processing software module, which significantly increases the efficiency, accuracy, and

robustness of mapping and surveying using GPS data. Using POSPac MMS in post

processing, one can obtain reliable decimeter level or better accuracy from existing reference

station networks without having a dedicated station located close to the project area.

In certain instances, POSPac data were post processed and evaluated for quality assurance

and development purposes. These data were not used for final sounding positioning.

Processed POSPac navigation data were internally implemented to confirm Coast Guard

DGPS navigation solutions and to corroborate system offsets. The program was also

employed to carry out limited water level QA/QC analysis.

A.3.13 Hydrographic Consultants, Ltd. CALLOAD

CALLOAD was installed on the side scan acquisition computer and used to initialize and

configure the SCC Smart Cable Counter. Sheave circumference, quantity of magnets and

preset cable out values were input into CALLOAD to reset the cable counter.

A.3.14 Trimble MS Controller

The Trimble MS Controller Software was installed on the multibeam acquisition computer

and used to configure the Trimble MS750 Receiver. It is a simulated keypad and display that

shows current position and a number of additional data fields, providing access to several

status and system setup menus.

A.3.15 Trimble ProBeacon

The Trimble ProBeacon PC Interface program was installed on the multibeam acquisition

computer and used to configure the Trimble ProBeacon to receive DGPS correctors from the

selected USCG station. The PC Interface Program was run through a DOS command

window to enter the receiver frequency, check the receiver status and monitor the RTCM

messages arriving from the ProBeacon to the acquisition computer.

A.3.16 ODIM Brooke Ocean MVP Controller

A dedicated laptop computer was used to operate the ODIM MVP30 Controller Software.

The System Configuration Window was used to interface the MVP towfish, MVP winch and

the navigation and depth data strings output from HYPACK. Position, depth and vessel

speed data were received from HYPACK and sound speed profiles were exported to

HYSWEEP to be used for real-time correction of the multibeam waterfall display.

The deployment configuration, alarms, and data logging options were set in the

Configuration Window, including profile depth limit, max cable out and docked cable out.


The deployment depth limit was set to 2 meters off bottom. Sound speed profiles (SV Files)

were saved to the MVP laptop and the .CALC files were post processed and converted to

CARIS .SVP files using Velocwin. During manual casts, completed once per day with the

vessel at rest, the MVP fish was allowed to reach full water depth.

The Main Operator Window was used to remotely “cast” the towfish and to monitor the

towfish parameters and alarms. Graphical tabs in the Main Operator Window were used to

monitor towfish depth and surface sound speed. The “view profile” button was utilized to

review the current sound speed profile. The manual logging option was toggled on during

the acquisition of stationary MVP casts.

A.4 Acquisition Procedures

A.4.1 Project Management Overview

All data acquisition and processing were performed under the supervision of the Chief of

Party. Field acquisition was performed under the supervision of a Lead Hydrographer and a

Senior Hydrographer, each with at least 3 years of experience conducting hydrographic

surveys.

A.4.2 Project Planning

Prior to the survey, a review of the current charted data was conducted to identify critical

features and areas including ship channels, fish havens, disposal sites and questionable

charted features (obstructions, wrecks, reported PA, ED charted features). General depth

areas were delineated from current charted information. A line plan was created to meet

requirements specified in the SOW. Specific line plans and survey coverage are described in

the individual survey Descriptive Reports.

A.4.3 Data Acquisition Quality Control

Data acquisition quality control was established and performed to ensure survey data met

requirements specified in the SOW and HSSD, 2010. The following quality control checks

were performed during survey operations:

Position

o Positioning system confidence checks were performed at every refueling or

weather delay stop relative to an NGS OPUS-derived or DGPS-derived temporary

dockside reference point (See HVCR).

o The POS MV position accuracy status indicators were monitored in real time.

o Position information from the primary and secondary DGPS receivers were

continuously compared in HYPACK and status indicators were monitored in real

time.


Attitude

o The POS MV GAMS heading accuracy status indicator was monitored in real

time.

o The POS MV heave, pitch and roll accuracy status indicators were monitored in

real time.

o TrueHeave and POSPac data were acquired at least 5 minutes prior to and after

SWMB acquisition.

Static Draft

o Static draft measurements were conducted prior to SWMB acquisition and daily

throughout the period of data acquisition.

o Additional static draft measurements were conducted before and after fueling.

Sound Speed Profile (SSP)

o The moving vessel profiler was operated in accordance with the ODIM Brooke

Ocean’s MVP30 Operation and Maintenance Manual.

o The SBE 19+ CTD was operated in accordance with Coast Surveys Development

Lab (CSDL) guidance: 3 minutes of warm up at the surface, 2 minutes operation

at the surface, 1 meter per second depth descent.

o Sound speed profile data were acquired with the ODIM MVP30 as deemed

necessary by the Hydrographer while recording multibeam trackline data. The

typical interval between MVP casts was on the order of 20 to 60 minutes.

o Casts were acquired to measure sound speed for the deepest depths of the survey

in accordance with the HSSD, 2010. All casts were reviewed and the profiles

extended in Velocwin.

o Simultaneous MVP and CTD comparison casts were acquired daily in the relative

location of operations when the R/V Ferrel was at a full stop. Daily MVP and

CTD confidence checks were performed and logged in Velocwin by comparing

the MVP/CTD surface sound speed to the SBE37 surface sound speed probe.

o Weekly confidence checks were performed and logged in Velocwin by comparing

sound speed profiles from the MVP and CTD.

o Casts were combined and reviewed in a custom MS Excel worksheet and graph

(Figure 2) to monitor cast-to-cast differences and daily variations.


Figure 2. Typical SSP Comparison in Microsoft Excel.


SWMB

o Surface sound speed sensor operation and UTC clock synchronization were

verified before SWMB acquisition commenced and frequently throughout each

survey day.

o A weekly bar check was performed to verify echo sounder draft offset and system

sounding accuracy.

o Weekly lead line or spot check comparison was performed to verify echo sounder

accuracy.

o The Reson real-time sounding profile “wedge” was monitored in real time.

o Real-time SWMB waterfall displays and digital terrain model coverage displays

were monitored in HYPACK HYSWEEP.

SSS

o The pressure sensor was calibrated daily prior to towfish deployment.

o The cable payout meter was initialized daily prior to SSS acquisition.

o Cable payout meter confidence checks were performed regularly using measured

marks on the towfish cable.

o SSS imagery confidence checks were recorded frequently on recognizable

features (e.g. sand waves, bottom texture changes).

o A slant-range corrected SSS waterfall display was monitored in real time. Contact

targets were positioned from the slant-range corrected data and displayed on the

helmsman map.

o An uncorrected SSS waterfall display was monitored in real time to observe water

column interference and nadir contacts.

Digital Acquisition Logs

o Daily activities

o Weather and sea state observations

o Survey trackline ID and time

o Unusual conditions and events

o Water column noise

o Vessel traffic and interference

o Significant contacts

o Deviation from planned tracklines

o Data gaps


B. PROCESSING AND QUALITY CONTROL

B.1 Data Flow and Processing Procedures

B.1.1 Sound Speed Profile Processing

Sound speed profiles (.svp format files) were derived from raw CTD and MVP data using

Velocwin software. Procedurally, daily sound speed profiles, attributed with position and

time of cast information, were concatenated for use in sound speed correction of survey lines

in CARIS HIPS.

B.1.2 SWMB Processing

SWMB processing procedures were designed to meet all requirements described in the SOW

and HSSD, 2010.

I. Multibeam Sonar Conversion and Batch Processing

Multibeam sonar data conversion and application of sounding correctors were completed

using the CARIS HIPS Batch Processor. The Batch Processor runs a user defined script

which accomplishes the following standard tasks without user intervention:

1. Convert the pre-process HYPACK HYSWEEP .HSX and .RAW data to the

HDCS data format.

2. Load daily TrueHeave files.

3. Load zoned, observed preliminary tides or verified tides once available.

4. Load and apply sound speed (SS) profile data. SS profiles were generally loaded

with the CARIS nearest in distance within time correction method.

5. Merge data to apply heave, vessel offsets/alignment, position, attitude, tide, and

dynamic draft correctors to bathymetry. HIPS computes the fully corrected depth

and position of each sounding during the merge process.


6. Compute TPU. Total Propagated Uncertainty (TPU) is calculated in CARIS

HIPS from contributing uncertainties in the echo sounder, positioning and motion

sensor measurements as well as uncertainties associated with sound speed and

water level correction. The standard CARIS devicemodel.xml was used to create

the HIPS Vessel File (HVF). HVF uncertainty values are provided in Section C.1

Vessel Configuration and Offsets. Sound speed TPU values were estimated from

manufacturer accuracy of the ODIM MVP-30, SBE19+ and SBE37. Tide and

sound speed values entered as “Survey specific parameters” in the CARIS HIPS

“Compute TPE” wizard were in accordance with guidance from HSSD, 2010,

Sections 4.1.6 Error Budget Considerations and 5.2.3.6 Uncertainty Budget

Analysis for Depths (Figure 3). (TPU is currently referred to as Total Propagated

Error, TPE, in HIPS Version 6.1 and will be modified to TPU in the subsequent

version).

Figure 3. Tide and Sound Speed TPU parameters.

7. Filter data according to the following criteria:

a. Reject soundings beyond 60o off-nadir to remove outer beam noise and

potential refraction errors.

b. Reject soundings with poor quality flags, (0 and 1 for Reson system).

II. Preliminary BASE Surface Generation

Preliminary BASE surfaces were created using the CARIS Uncertainty algorithm for

reviewing and cleaning full-density soundings. Daily data review and cleaning were

performed using 1–5-meter resolution BASE surfaces as a guide for directed editing. Depth,

Standard Deviation and Shoal surface models were viewed with vertical exaggeration and

sun illumination to highlight areas that would require immediate investigation. Standard


deviation BASE surfaces were reviewed to evaluate data for consistency between

overlapping coverage and cross lines; and to detect potential systematic position, motion,

tide, or sound speed errors.

III. Data Cleaning and Editing

1. Line attitude and navigation data were reviewed in their respective CARIS editors

to ensure that there were no problems with the correctors, such as gaps in attitude

or navigation jumps. Extreme speed jumps were rejected with interpolation and

data were re-merged, if needed.

2. The CARIS Swath Editor was used to clean noise, multipath returns, and gross

fliers which are most easily reviewed and edited in this time-based (ping) display.

Data were filtered on a line-by-line basis to isolate unique environmental

conditions, events and features. Soundings were colored by depth and reviewed

in multi-directional profile and 3-dimensional displays. Tracklines and swath

boundaries were viewed in the CARIS Map window in reference to BASE

surfaces, charted data (RNC, ENC), SSS contacts and field annotations

(HYPACK target files).

3. The CARIS Subset Editor was used to clean fully-corrected, geospatially located

soundings in 2-D and 3-D displays. Soundings were colored with line, depth and

uncertainty attributes. Areas with multiple sounding coverages from adjacent

survey lines were evaluated to increase confidence in outer beams and over

significant features. Subset boundaries were viewed in the CARIS Map window

in reference to BASE surfaces, charted data (RNC, ENC), SSS contacts and, at

times, field annotations (HYPACK target files). A complete final sounding

review was performed for the entire survey coverage area and tracked with subset

tiles.

4. The Designated Sounding flag identifies the shoalest sounding of a feature. The

purpose of the Designated Sounding flag is to ensure that the shoalest depths over

significant seabed features or shoals are maintained in BASE surfaces (see

following section), charts and other standard hydrographic products.

IV. BASE Surface Sounding Selection (Designated Soundings)

In areas of significant shoaling, critical soundings were designated on outstanding shoals and

features to ensure the representative least depth for the area would be included in the final

BASE surfaces. BASE surfaces were reviewed to ensure that shoal soundings were

accurately represented by the surface resolution. For water depths ≤20 meters, soundings

were designated on any object that had a difference between the gridded surface and reliable

shoal depth greater than one half the allowable IHO Order 1 error budget for that depth. For

water depths >20 meters, soundings were designated on any object that had a difference

between the gridded surface and reliable shoal depth greater than the allowable IHO Order 1

error budget for that depth. Near nadir soundings were designated as least depths on shoal

features in lieu of outer beam soundings whenever possible. Full density soundings were

reviewed for each SSS contact in the CARIS Subset Editor and a sounding was designated


for the representative least depth of each significant contact (or Primary/Secondary contact

pair).

V. AWOIS, Contact and Feature Development BASE Surface Creation

When necessary, in addition to mainscheme data acquisition, development/investigation lines

were run over AWOIS items, significant contacts and other features observed in SWMB and

SSS records to meet the HSSD, 2010 Object Detection Coverage specification (Section

5.2.2.1). Once an item was deemed significant, nearly significant, or simply required more

data to make a determination, a series of short, high density sounding lines were run over the

feature. Fifty-centimeter resolution CUBE BASE surfaces were created over each feature

and the immediate surrounding seabed to inspect sounding density. A 50-centimeter BASE

surface was created using the CARIS HIPS implementation of the CUBE (Combined

Uncertainty and Bathymetry Estimator) algorithm with advanced CUBE parameter settings

configured to prove/disprove Object Detection Coverage. The Capture Distance Scale and

Capture Distance Minimum parameters were modified such that only the soundings that fell

within a fixed radial distance of 0.35 meters of a node were used to calculate sounding

density.

VI. Final BASE Surface Creation

Final BASE surfaces were created using the CUBE algorithm. The CUBE algorithm

generates surface models from multiple hypotheses that represent the most accurate possible

depths at any given position. Hypotheses with lower combined Total Propagated Uncertainty

(TPU) are given higher significance for incorporation into the final surfaces.

The following options were selected when final CUBE surfaces were created:

Surface Type – CUBE

IHO (International Hydrographic Organization) S-44 Order 1

Include status – Accepted and Designated

Disambiguation method - Density & Locale

Shallow configuration (Figure 4).

Final BASE surfaces were created to meet minimum requirements specified by the HSSD,

2010. For mainscheme multibeam bathymetry acquired concurrently with 200% side scan

coverage ("skunk stripe"):

Grid resolutions of 1 meter for depths 0-22 meters and 2 meter for depths 20-44

meters.

Within the swath, minimum sounding density shall be 5 soundings per node.

No full swath width, along-track, holiday spanning more than 3 nodes in waters

less than 30 meters or over tops of potentially significant features.


Critical soundings were incorporated into the BASE surfaces when finalized. Final BASE

surface resolutions are unique for each survey area and are described specifically in the

respective descriptive reports.

Figure 4. Example of CUBE Parameter selection.


VII. Sounding Density BASE Surface Creation

The Density Attribute Layer for CUBE BASE surfaces was used to evaluate the

sounding density for fixed node spacing. The Density sounding selection area is

based upon two CUBE parameters:

1. The Capture Distance Scale (CDS) defines a radial distance from the node which

is based upon a percentage of water depth. The CDS value can range from 1 to 10

percent of the water depth. All soundings within this radius are included in the

Density value (and propagated to the node).

2. The Capture Distance Minimum (CDM) defines a fixed radial distance in meters

from the node in which all soundings are included in the Density value (and

propagated to the node).

The maximum value of the two capture distance parameters is used to set the actual

capture distance. These values can be manipulated to ensure that the capture distance

minimum is the determining factor for the radius of influence and, therefore, define a

fixed radius for calculating the sounding density.

Example for a 2-meter BASE surface in depths less than 30 meters:

CDS = 1

CDM = 2 / root(2) = 1.414 (maximum propagation distance defined in section

5.2.2.1 of the HSSD, 2010)

The CDS radius maximum value (0.01 * 30 = 0.3 meters) will not exceed the CDM

value (1.414 meters) for the maximum depth, and therefore the Density Attribute

Layer will represent those soundings that lie within a fixed radial distance (1.414

meters) for all nodes. A CDM value of 0.707 was used for 1-meter BASE surfaces.

“Density” BASE surfaces were created for individual survey field sheets by adjusting

the CDS and CDM values such that no soundings beyond the maximum propagation

distance, defined by surface resolution, were contributing to each grid node. The

Density surfaces were reviewed to ensure that the minimum sounding density of at

least 5 soundings per node was met. Survey field sheets contain the Density BASE

surface along with the finalized BASE Surface generated with the Shallow

Configuration CUBE parameters (See Section VI).


VIII. Combined Final Surface

All finalized BASE surfaces were combined at the resolution of the largest grid size of any

one contributing surface. The combined final surface was used to generate contours and

soundings for chart comparisons and final product review.

IX. Quality Control (QC)

1. Cross Lines

Cross line data were acquired in accordance with the HSSD, 2010. Statistical

quality control information is generated by comparing the beams of each cross

line to a combined BASE surface. Cross line evaluations are performed with

respect to IHO Order 1 uncertainty specifications with the CARIS QC Report

Utility, and are presented in Separate IV of the DR.

2. BASE Surface QC Reports

The TPU values for final BASE surface depths were evaluated with the CARIS

BASE surface QC Report Utility with respect to IHO Order 1 uncertainty

specifications. BASE surface QC reports are presented in Separate IV of the DR.

B.1.3 Side Scan Sonar (SSS) Processing

SSS processing procedures were designed to meet all requirements described in the SOW

and HSSD, 2010. Side scan sonar data were processed using CARIS SIPS and the following

processes/procedures:

1. Convert the pre-process CTI SonarWiz XTF data to the HDCS data format in

CARIS’ Conversion Wizard. Vessel trackline positions were converted from the

XTF bathymetry/ship position field. Towfish positions were converted from the

XTF sensor position field and fish heading was computed from course made good

(CMG) from vessel navigation. SonarWiz calculated the towfish position from

layback and fish depth; therefore, it was not necessary to re-compute the towfish

navigation or position in CARIS SIPS.

2. Line attitude and navigation data were reviewed in their respective CARIS editors

to ensure that there were no problems with the correctors, such as gaps in attitude

or navigation jumps. Extreme speed jumps were rejected with interpolation.

3. SSS line imagery was reviewed in CARIS SIPS for water column interference and

accurate bottom tracking. Bottom tracking was re-digitized when necessary,

automatically by SIPS, or manually to ensure accurate slant range correction.

4. Slant range correct SSS imagery – A flat-bottom model and 1500 meter/second

sound velocity was used to slant range correct line imagery at 0.1-meter

resolution.

5. Angle-varying gain correction (AVG) – Angle-varying gain correction was

applied to slant range corrected SSS imagery to normalize angular response from

varying sediments.


6. Time-varying gain correction (TVG) – Time-varying gain correction was applied

to slant range corrected SSS imagery to adjust the signal intensity in the port and

starboard channels, as needed.

7. Contact processing:

a. Slant range corrected line imagery was reviewed in SIPS to identify objects by

the presence of sonar shadows.

b. Shadow lengths were measured and converted to heights.

c. Contacts with significant heights were positioned and created at the top of the

shadow. Significant contacts were identified based upon height above the

seafloor bottom in accordance with the SOW and HSSD, 2010 (Table 4).

d. Contacts were attributed with the following information:

i. Height

ii. Width (if significant)

iii. Length (if significant)

iv. Feature type (e.g. rock, obstruction, wreck, unknown)

v. Processor remarks

Table 4

Significant Contact Selection Criteria

Surrounding Depth or Area

(meters)

Significant Contact Height

(meters)

0-20 1

>20 10% of surrounding depth

8. Contact correlation and bathymetric feature resolution:

a. All contacts were visually correlated between 100% and 200% coverages in

the CARIS Map window (Figure 5). Once correlated, contacts were evaluated

with respect to BASE surfaces (i.e. depth and standard deviation), charted

information, trackline swaths, and designated soundings. All significant

contacts (or contact pairs) were evaluated in full density sounding subsets to

ensure that there was adequate SWMB coverage. Soundings were designated

on all significant contacts to obtain an accurate position and least depth.

b. Significant contacts were visually correlated with designated soundings in the

CARIS Map window.


Figure 5. CARIS Map View Correlation Window.

c. Contacts, contact images and designated soundings were exported from

CARIS. These data were processed with MS Excel to produce a contact

spreadsheet as specified in the SOW and HSSD, 2010 (Section 8.3.2). A

custom macro displayed contact images and remarks, calculated contact and

designated sounding relationships (i.e. distances, depths), updated processing

flags/remarks and associated contact/sounding pairs (Figure 6). Unique

contact ID’s were created from line-profile-range data. The contact

spreadsheet is attributed with NAD83 positions and can be imported into a

GIS.


Figure 6. Spreadsheet correlation macro.

d. The contact spreadsheet was imported into a Microsoft Access database. Each

record contained the contact’s image, attribution and feature flagging, the id

and image of its correlating contact, and the designated sounding id and depth,

if one had been assigned in the Excel correlation macro. An example of a

contact record from OSI’s custom Access database is shown in Figure 7. The

contact database file is submitted with the contact spreadsheet in DR Separate

V.


Figure 7. Contact Record from the Microsoft Access Database.


B.1.4 S-57 Feature Processing

An S-57 feature file was created in CARIS Notebook to emphasize navigationally significant

objects discovered during the survey and to provide information for these objects that could

not be portrayed in the BASE surfaces. Features’ depths (VALSOU – value of sounding)

and positions were extracted from soundings generated from the final combined BASE

surface. Bottom samples were included as attributed SBDARE (Seabed Area) point objects.

Separate CARIS HOB format files and a combined S-57 format .000 file were created for

each survey.

All S-57 features were attributed in accordance with guidance provided in the SOW and

HSSD, 2010 using the following conventions:

INFORM was used for survey descriptive information to aid in chart application.

SBDARE bottom sample object INFORM attributes contain the original field

descriptions of the sediment samples.

SORDAT was attributed with the final date of the survey.

SORIND was attributed with the country codes and survey registry (e.g. US, US,

Surveys, H12236).

C. CORRECTIONS TO ECHO SOUNDINGS

C.1 Vessel Configuration and Offsets

C.1.1 CARIS Vessel Configuration Files and Device Models

SWMB CARIS Vessel Configuration Files (.HVF format with TPU calculation) were created

to convert HYPACK .RAW and .HSX data files. The Reson 7101 device was configured

from the default CARIS devicemodel.xml. Multibeam data were converted from

.RAW/.HSX line file pairs. All raw geographic position data were converted from the

HYPACK .RAW format line files. All raw attitude sensor data were converted from the

.HSX file structure. Vessel offsets, alignments and sensor installation accuracies were

entered into the .HVF and used for TPU calculation. General vessel configuration and

horizontal offsets are depicted in Figure 8.

SSS CARIS Vessel Configuration files were created to convert CTI SonarWiz .XTF data

files. The SSS vessel file is a “zero” configuration because all towpoint offset and layback

calculations were performed in SonarWiz. No additional towfish position calculation was

necessary in CARIS SIPS.


Figure 8. R/V Ferrel equipment offsets and configuration.


C.1.2 Offsets and Uncertainty Estimates

Tables of instrument offsets and Total Propagated Uncertainty (TPU) values input to the

CARIS vessel configuration file are included in Tables 5-7 below. A bar check was

performed prior to survey data acquisition to measure the transducer phase-center vertical

offset with respect to the vessel reference point.

Table 5

R/V Ferrel Sensor Offsets (see Figure 8)

R/V Ferrel Offsets via Topcon Total Station

Survey. Offsets are relative to Reference

Point (R/P) or Waterline

Forward

Positive

(m)

Starboard

Positive

(m)

Up

Positive

w.r.t R/P

(m)

Up

Positive

w.r.t. Waterline

(m)

R/P IMU Center 0,0,0 0.000 0.000 0.000 -0.840

GPS POS Antenna Phase Center Port 12.029 -2.377 10.962 10.122

GPS POS Antenna Phase Center Starboard 12.064 2.427 10.957 10.117

GPS Antenna Phase Center 15.383 2.110 11.047 10.207

Transducer Phase Center 1.476 5.260 -1.770 -2.610

Top Of Sheave (Wire at top of sheave) -18.550 2.040 4.080 3.240

Table 6

R/V Ferrel CARIS Vessel File Transducer Offsets (RP to Tx)

Tx Offsets IMU/Navigation to

Transducer (m)

X Phase Center 5.260

Y Phase Center 1.476

Z Phase Center 1.770

Table 7

R/V Ferrel CARIS Vessel File TPU Estimates

TPU Values Included in CARIS VCF

Gyro Measurement Error (deg) 0.01 Pitch Timing Error (sec) 0.01

Heave % Amplitude 5.00 Roll Timing Error (sec) 0.01

Heave Error (m) 0.05 Vessel Speed Error (m/s) 0.03

Roll Measurement Error (deg) 0.02 Loading Error (m) 0.03

Pitch Measurement Error (deg) 0.02 Draft Error (m) 0.03

Navigation Measurement Error (m) 2.00 Delta Draft Error (m) 0.03

Transducer Timing Error (sec) 0.01 Tide Measurement Error (m) 0.10

Navigation Timing Error (sec) 0.01 Tide Zoning Error (m) 0.20

Gyro Timing Error (sec) 0.01 Sound Speed Error (m/s) 0.30

Heave Timing Error (sec) 0.01 Sound Speed Error Surface (m/s) 0.20


C.2 Static and Dynamic Draft Measurements

C.2.1 Static Draft

Prior to data acquisition, the R/V Ferrel was secured to a pier in very calm conditions. A

number of physical measurements were then made from both port and starboard draft

observation locations to the water surface. During this period, the Hazen tide gauge (input to

HYPACK) was used to record water levels. The Hazen data were processed and compared

to the physical measurements. The delta between these datasets was determined and

subsequently used to convert Hazen water level information to static draft.

While underway, survey operations were suspended once per day on the R/V Ferrel and the

vessel was brought to a full stop, enabling a static draft measurement. Hazen gauge

measurements were acquired daily. On calm days, static draft was measured from permanent

benchmarks on both starboard and port sides to the waterline using a fiberglass stadia rod and

compared to the Hazen gauge water level measurement. Vessel attitude was accounted for as

the final measured static draft value is an average of the port and starboard measured values.

However, on most days, the water surface was too rough for a reliable physical measurement.

The static draft measurement was calculated daily using the Hazen tide gauge method. The

draft measurement was corrected to the vessel reference point and recorded in the acquisition

log. Static draft values calculated from the Hazen gauge data were time stamped and entered

into the CARIS HIPS .HVF under Waterline Height.

C.2.2 Settlement and Squat (Dynamic Draft)

The dynamic draft was determined using RTK GPS methods. A GPS base station was

established onshore near the test area and the POS MV was configured to operate in RTK

“FIX” mode. Position and elevation data were obtained as the vessel transited “up and

down” a pre-determined trackline at a set RPM. Tidal variations were accounted for by

recording the GPS position and elevation values with the vessel at rest (i.e. dead in the water)

at the beginning and end of each RPM-setting reciprocal line pair. Dynamic draft

measurements were made at select RPM intervals within the range of possible survey speeds.

The final dynamic draft values were then determined by averaging the results of each RPM

pair. The data points displayed in Figure 9 and noted in Table 8 were entered in the CARIS

vessel file.


Figure 9. R/V Ferrel Dynamic Draft Curve.

Table 8

R/V Ferrel Dynamic Draft Correctors

R/V Ferrel 7101 Multibeam/SSS Dynamic Draft Correctors

RPM's Speed Dynamic Draft Correction

Both Engines

(unless noted) M/S Knots Meters

680 (1 engine) 1.89 3.67 -0.002

680 2.52 4.89 0.024

800 3.04 5.91 0.029

900 3.47 6.74 0.051

1000 3.79 7.37 0.075

1100 4.10 7.97 0.077

1200 4.43 8.61 0.086


C.3 Motion, Timing Errors and Sensor Alignment

An Applanix POS MV 320 V.4 was employed for motion, heading, and position

determination. Manufacturers stated accuracy and resolution values are tabulated below in

Table 9.

Table 9

POS MV Specifications

POS MV 320 V.4 Manufacturers Specifications

Parameter Accuracy Resolution

Roll 0.02° 0.01°

Pitch 0.02° 0.01°

Heave 5cm or 5% of

wave height 0.01m

Heading 0.02° 0.01°

Prior to commencement of survey operations, a sensor alignment or patch test was

performed. The initial patch test for the R/V Ferrel was performed on April 5, 2010 (DN

095). The patch test was conducted to determine biases in roll, pitch, heading and navigation

timing. Data were acquired in accordance with Section 5.2.4.1 Multibeam Sonar Calibration

from the HSSD, 2010. Initial patch test calibrations were accomplished employing RTK

GPS positioning and water level determination.

Patch test lines were run multiple times to ensure system repeatability. Patch test biases were

determined in the following order: navigation timing error (latency), pitch, roll, and heading.

The CARIS HIPS Calibration Tool (Figure 10) was used to determine final offset values.

However, all patch test values were verified with the HYPACK HYSWEEP patch test

routine (Figure 11).

For each parameter, multiple processing iterations were performed. The final offset values

are an average of the CARIS-derived values. The final applied values, entered into the

CARIS vessel files (HVFs), are shown in Table 10. The patch tests results were of high

quality and repeatability.

Table 10

Initial R/V Ferrel Patch Test Alignment Correctors

CARIS Patch Test Results

Latency 0.0 sec

Pitch -0.25 deg

Roll 0.44 deg

Yaw (heading) -0.30 deg


Figure 10. CARIS HIPS Calibration Tool.

Figure 11. HYPACK HYSWEEP Patch Test Utility.


C.4 Water Levels

The tidal datum for this project is Mean Lower Low Water (MLLW). All sounding depths

are referenced to MLLW. The operating National Water Level Observation Network

(NWLON) station at Panama City, FL (872-9108), served as datum control for this project.

The Panama City, FL (872-9108) NWLON station is the reference station for predicted,

preliminary observed and verified tides for all hydrography for this project. The time and

range ratio correctors for applicable zones were applied to all tide correctors in CARIS HIPS

during the preliminary and final processing phases of this project. Predicted and preliminary

observed zoned tides were applied to sounding data for preliminary processing. Verified tide

data were downloaded from the NOAA CO-OPS Internet page

http://tidesandcurrents.noaa.gov/ and applied with final zoning for all final soundings and

BASE surfaces. Water levels used for DTON submissions are specified in the reports.

Additional information is provided for this survey in the HVCR and DR.

http://tidesandcurrents.noaa.gov/olddata


D. APPROVAL SHEET

LETTER OF APPROVAL

REGISTRY NOS. H12236 AND H12237

This report and the accompanying data are respectfully submitted.

Field operations contributing to the accomplishment of Surveys H12236 and H12237 were

conducted under my direct supervision with frequent personal checks of progress and

adequacy. This report and associated data have been closely reviewed and are considered

complete and adequate as per the Statement of Work.

George G. Reynolds

Ocean Surveys, Inc.

Chief of Party

December 23, 2010

u.s. department of commerce national oceanic and ... · registry nos. hydrographic title sheet...

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